I probably wouldn't really go either personally but if I had to choose DB Apex. At least the Apex is decent tubing (Tange Double Butted if not mistaken) and some decent enough parts of the era. The bad boy looks like a cheap hybrid that someone is trying to get their money back from. If the bikes were both at the same price of $100 I might say Cannondale simply for newer parts which are cheap and not all that great but could possibly be in slightly better shape and good disc brakes are nice (so this would give you some upgrade opportunities).
Obviously this is all assuming the bikes fit and are comfortable. If they don't then none of this matters and you should get a bike that fits.
In searching the Apex I came across this which I like:
https://www.pedalroom.com/bike/1987-...ack-apex-29602
Any bike you come up with even some new bikes some things to upgrade that don't cost a lot but make a world of difference would be:
Brake pads and shoes. Make sure they are removable so all you need to do is just get pads they will be stiffer and offer better braking performance and save you in the long run. SwissStop is my main go to but for some bikes Kool Stop has what I need (especially older nutted pads)
Cables and housing. If you want to add some bling the Jagwire Elite Link Housing is excellent, it cuts weight and the beads are reusable with the new inner lining costing $5-10 or so and they come in different colors and with really smooth slick cables. If not those anything with a good slick stainless steel cables (no galvanized ever for any reason) and decent housing will work. My top choice if not Elite would be Jagwire Pro or even the sport and those you can get in different colors as well.
Tires. I lke a good supple tire personally but for touring something with a bit more protection is helpful. Look for folding beads as those are usually lighter and certainly pick a tire based on your terrain. If road touring find something slicker if off road then get a decent gravel tire or XC oriented mountain tire. Continental and Schwalbe make some good touring tires but I do really like the Graphene that Vittoria is using.
Grips. I want something that I won't slip on easily and that doesn't wear out or get gummy quickly but most important is comfort. Ergon, Ergon and Ergon are the choices for really comfortable durable grips for all of my flat/alt bar bikes. The flat palm section offers better blood flow and the Biokork looks nice and is potentially slightly greener.
Pedals. Life is too short to ride cheap pedals. A good pedal should use sealed bearings (or a mix of sealed bearings and bushings) and good grip (replaceable pins are great) and ideally not plastic. If I am going Clipless for touring the T8000 pedals are the way to go, XT SPD on one side and a nice grippy MTB flat pedal on the other. For flat pedals Crank Bros is a good choice as on all levels of their pedals they are using sealed bearings and high quality bushings however I do like my MKS Lambda/Grip King pedals (though wish they had pins)
Certainly other upgrades like saddle are important as that is another touch point but those will cost a bit more and are well worth the extra cost. Chain, cassette, chainrings aren't really super important to upgrade but make sure they aren't worn out and are clean and properly lubricated though you can lose some weight and in some cases get a little better shifting performance out new stuff. If you decide to go 1x then a good narrow wide chainring will be helpful (Race face isn't super expensive and works well).
Wheels are another big upgrade but can be well worth it. A good set of handbuilt wheels by someone who knows what they are doing with high quality parts can last a lifetime. I prefer sealed bearing hubs so I don't need to mess with them often and for a touring bike I would look for hubs that are 32 or 36 hole and a good stout rim designed for touring. My favored spokes and nipples for this application are Sapim Strong and Secure Lock BRASS nipples but the Alpine III spokes from DT Swiss are also good as are the corresponding locking BRASS nipples. If it were me I would probably go with something like a White Industries Hub (MI5 for rim and XMR or CLD for disc) and Velocity Dyad or Atlas Rim so I can support U.S. manufacturing and quality products but you can find some cheaper stuff depending on what you need. For ultimate versatility you might consider going with a disc brake hub and a rim brake compatible wheel and you just don't use what you don't need and if you upgrade to a different bike those wheels could possibly follow.